Since the great rush for natural gas in the United States, environmentalists have been torn on the fuel's benefits for alleviating climate change. It produces less carbon dioxide emissions than coal for electricity or gasoline and diesel for fuel, but even a small amount of natural gas release -- which is essentially methane -- packs a greenhouse gas punch about 30 times more powerful than the same amount of carbon dioxide.

The trick to lowering natural gas's global warming quotient is to tighten up leaks in upstream operations, from extraction to use, say the authors of a World Resources Institute report released today. Federal and state officials should step up and promote measures that limit methane, toxic pollution and smog-forming agents, the report concludes.

U.S. EPA has begun the process of requiring natural gas companies to use "green completions," a set of technologies and methods that allow for an efficient and leak-free transfer of natural gas from extraction wells to transport pipelines to the refineries or processors.

"The control technologies are highly cost-effective," said James Bradbury, one of the authors of the report and a senior associate in the World Resources Institute's Climate and Energy Program. "We can get significantly lower emissions."

While leakage rates of "fugitive methane" are currently around 4 percent according to EPA, they need to be at less than 1 percent of total production. This can be achieved by reducing emissions by one-third to half of current levels, according to the report.

Nevertheless, write the authors, leakage rates in the production phase vary greatly from study to study, with one Cornell University Study placing the figure at 9 percent.

Methane lawsuit threat hangs over EPA's head
Research by the Environmental Defense Fund has found that leakage rates must remain below 3.2 percent for natural gas power plants to carry a climate advantage over coal plants.

Last year, EPA finalized a set of New Source Performance Standards for the oil and gas industry limiting smog-creating volatile organic compounds (VOCs) and hazardous air pollutants. EPA said these standards would carry a co-benefit of cutting methane emissions, as well.

But some say this is not enough. EPA must take the extra step to craft performance standards for greenhouse gases as well as VOCs and hazardous pollution, they say. In December, seven states led by New York threatened to sue EPA if the agency failed to directly address methane from the oil and gas industry (Greenwire, Dec. 11, 2012).

The benefits of EPA's implementing standards for greenhouse gases would be twofold, Bradbury said. They would cover not only methane emissions but carbon, which is emitted through the use of compressors at various stages of the supply chain. They would also resolve leakage issues when methane reduction is no longer a co-benefit of agency standards. This applies in the chain after the processing step, when there are much less volatile organic compounds -- the smog-causing agents -- to clean up, said Bradbury.

Natural gas production grew by nearly a quarter between 2007 and 2012 and has held steady over the past year, according to the Energy Information Administration. There are about 500,000 gas wells in the country, said Bradbury, and 300,000 miles of pipelines.

Representatives of the industry disagree with an automatic call to regulation. It is surprising that the WRI experts admit to uncertainty over emissions yet suggest that more regulation that could hamper smaller producers, said Steve Everley, spokesman for Energy in Depth, a campaign by the Independent Petroleum Association of America.

"To do what, exactly?" wrote Everley in an email. "Arbitrarily imposing new taxes and redundant regulations on responsible shale development would directly undermine that achievement, and quite likely reverse it."

Voluntary methane program could play a role
Everley, as well as a spokesman for the American Petroleum Institute, has said that the industry has made significant technology upgrades to reduce leakage as production rises. According to a 2011 report from EPA, methane emissions from natural gas systems have declined since 2005.

Natural Gas STAR, a voluntary emissions program at EPA, could also play an important role creating a bridge to industry, said Bradbury. It could be expanded and given better resources and could act as a clearinghouse and database for natural gas companies. Awards and public recognition, such as via EPA's Energy STAR program, could also create incentives.

But Natural Gas STAR may not be the industry's preferred venue. Devon Energy Corp., a major producer, recently quit the program over concerns that the agency was miscalculating data in order to justify regulations (Greenwire, March 11).

Finally, said Bradbury, the financial benefits for implementing green completions often fall disproportionately on the production company, and processors down the line gain less from their investments.